Your employee clicks what looks like an innocuous bit.ly link in an email. Seconds later, they’re on a convincing fake login page, credentials entering the attacker’s hands before anyone realizes what happened.
What you just read isn’t a made up story. It’s a typical Tuesday.
URL shorteners like bit.ly, TinyURL, and the 1,200+ other redirect services cataloged in our database are common tools of modern digital life. They’re convenient, trusted, and unfortunately, routinely weaponized by threat actors to legitimize malicious links.
The problem isn’t the link shortener services themselves. The problem is that they’ve become the perfect Trojan horse for phishing campaigns, malware distribution, and social engineering attacks. And the typical enterprise response…blocking them entirely…creates more problems than it solves.
Why Attackers Love Public Redirect Services
Link shorteners are a gift to attackers, and here’s why:
Obscuration. The entire point of a URL shortener is to hide the destination. That bit.ly/x7Kp2m link? It could lead to your company’s genuine HR portal or a credential harvesting site in Belarus. Your users (and your security tools) have no way to tell until it’s too late.
Trust exploitation. Domains like bit.ly, tinyurl.com, and goo.gl have legitimate reputations. They appear in marketing emails, social media posts, and internal communications daily. Attackers leverage this ambient trust ruthlessly. An email from “IT Support” with a bit.ly link feels less suspicious than one with randomstring.xyz—even when the destination is identical.
Evasion. Traditional URL filtering relies on blacklists and reputation databases. By the time a malicious destination gets flagged, the attacker has already moved on, or simply created a new shortened link pointing to the same payload. The redirect service itself is never blocked because it’s legitimate. The actual threat remains invisible until the redirect completes.
For many white collar workers this is an everyday occurrence. So we catalogued over 1,200 known public URL redirect services, and that number grows constantly. Each one represents another potential avenue for obfuscated attacks.
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Which Threat Feeds Are You Interested In?
Domainsure offers specialized threat intelligence feeds designed for organizations that can’t afford to be blindsided:
Crypto Defender – Domain and DNS protection for Web3 projects
Domainsure Verified Hostiles – Curated threat actor domains and infrastructure
Public URL Redirect List (PURLs) – 1,200+ catalogued redirect services
PURLs Redirect Intercept Appliance – Pattern interrupt technology in action
[Request Access] to explore which feeds fit your security posture.
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The “Just Block Them All” Problem
The knee-jerk security response is obvious: if URL shorteners enable attacks, block them at the firewall.
Except as many IT Managers quickly find out, that doesn’t work.
Your marketing team uses bit.ly for campaign tracking. Your sales team shares TinyURL links with prospects. Your partners send shortened URLs in transactional emails. Your social media manager posts t.co links (Twitter’s built-in shortener) dozens of times per day.
Block all public redirects and you’ve just kneecapped multiple business functions. Worse, you’ve trained your users to see security as an obstacle to productivity—which is how shadow IT and policy workarounds proliferate.
The operational cost of blanket blocking often exceeds the security benefit. And in a world where legitimate business communication increasingly happens outside your control (Slack, WhatsApp, SMS), attempting to enforce such policies is futile anyway.
So what’s the alternative?
A Smarter Solution: Pattern Interrupts
The answer isn’t blocking.
It is capturing attention and guiding awareness.
What if, instead of preventing employees from clicking shortened links, you simply made them aware they were clicking one, and gave them a moment to consider whether that makes sense in context?
That’s the concept behind pattern interrupts.
When a user clicks a public redirect link, instead of seamlessly forwarding them to the destination, you inject a brief notification:
“You are being redirected through a public URL shortener.
The destination is:
[actual-destination.com].
Proceed?”
It’s not a hard block. It’s a small speed bump. A moment of friction that allows the user’s threat detection instincts to kick in.
Here’s what makes this approach effective:
For employees: They get context without losing access. That bit.ly link from your colleague’s personal email? Makes sense—they’re working from home. That TinyURL in a “password reset” email from IT? Suspicious. You’d never send that through a third-party redirect service.
For security teams: You gain visibility into redirect usage across your organization without creating enforcement headaches. Logging these interactions provides intelligence: which departments use them, which external services appear most frequently, whether patterns suggest phishing campaigns.
For the organization: You preserve productivity while hardening defenses. Users aren’t blocked from legitimate business activities, but they’re also not sleepwalking into social engineering attacks.
See How It Works
The DS PURLs RPZ (Domainsure Public URL Redirects List Response Policy Zone) implements exactly this approach using DNS-layer controls. Instead of blocking public redirects at the firewall, it injects pattern interrupts into the redirect chain itself.
Watch how it works in practice:
In this demo, you’ll see how DS PURLs RPZ intercepts a shortened link, displays the actual destination to the user, and logs the interaction for security teams all without blocking access.
The system operates transparently. Your DNS infrastructure routes requests through the DS PURLs database of 1,200+ known redirect services. When a match occurs, instead of resolving directly to the shortener’s IP, it resolves to a notification page. The user sees the real destination URL, makes an informed decision, and proceeds (or doesn’t). Either way, your SOC gets a logged event.
—
Which Threat Feeds Are You Interested In?
Domainsure offers specialized threat intelligence feeds designed for organizations that can’t afford to be blindsided:
Crypto Defender – Domain and DNS protection for Web3 projects
Domainsure Verified Hostiles – Curated threat actor domains and infrastructure
Public URL Redirect List (PURLs) – 1,200+ catalogued redirect services
PURLs Redirect Intercept Appliance – Pattern interrupt technology in action
[Request Access] to explore which feeds fit your security posture.
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The Benefits of This Approach
Far too many security tools are deployed with a “set and forget” mentality—firewalls that block everything by default, antivirus that flags legitimate software, DLP that makes file sharing impossible. These create friction without intelligence.
Pattern interrupts are different. They’re intelligent friction.
Users aren’t infantilized. You’re not blocking them from doing their jobs. You’re giving them information to make better decisions. That’s a fundamentally different relationship between security and productivity—and one that actually increases compliance rather than driving workarounds.
Security teams get actionable intelligence. Every intercepted redirect is a data point. Are phishing campaigns targeting your finance department specifically? Are your sales reps inadvertently sharing customer data through public shorteners? You’d never know from traditional logs. Pattern interrupts surface these patterns.
The organization stays agile. New redirect services appear constantly. Maintaining blacklists is a losing game. By flagging the category (public redirect) rather than individual domains, you remain effective even as the threat landscape evolves.
And more importantly, you catch obfuscated phishing attempts before they succeed. That fake Microsoft login page hidden behind a bit.ly link? It gets exposed at the redirect layer, when the user still has time to recognize the actual destination and abort.
Implementation and Getting Started
The DS PURLs RPZ integrates with existing DNS infrastructure—whether you’re running internal nameservers, using managed DNS providers like Cloudflare or AWS Route 53, or some hybrid approach. It operates as a Response Policy Zone, a DNS firewall technology that’s been around for years and is widely supported.
What makes our implementation unique is the curated database behind it. We’ve catalogued over 1,200 public redirect services—not just the obvious ones like bit.ly and TinyURL, but the long tail of regional shorteners, niche tools, and emerging platforms that attackers increasingly use specifically because security teams aren’t watching them.
The list is continuously updated. New services appear; defunct ones are pruned. This isn’t a “set and forget” static list that goes stale. It’s a living database maintained by people who actually understand the threat landscape (that would be us—with 25+ years of experience in domain and DNS security).
Setup typically takes under an hour. We provide documentation, integration guides for common DNS platforms, and direct support if you run into edge cases.
And because pattern interrupts are fundamentally about visibility rather than control, you can deploy them in monitoring mode initially—log everything, block nothing—while you baseline normal usage patterns in your environment.
Conclusion
Public URL redirect services aren’t going away. They’re too useful, too embedded in how modern digital communication works. Attempting to block them entirely is security theater. It’s expensive, disruptive, and ultimately ineffective.
The smart approach is accepting their existence while adding a layer of intelligent protection. Not blocking. Not trusting blindly. But injecting awareness at the point where it matters most: when a user is about to follow an obfuscated link.
Pattern interrupts give your users and security teams what they actually need: visibility, context, and the ability to make informed decisions in real time.
Because at the end of the day, security isn’t about building higher walls. It’s about giving people the information they need to protect themselves.
Don’t block legitimate services, add intelligent protection. Learn more about DS PURLs RPZ and how pattern interrupts can strengthen your security posture without disrupting productivity.
Request Access or Contact Domainsure to schedule a demonstration or trial deployment.
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Which Threat Feeds Are You Interested In?
Domainsure offers specialized threat intelligence feeds designed for organizations that can’t afford to be blindsided:
Crypto Defender – Domain and DNS protection for Web3 projects
Domainsure Verified Hostiles – Curated threat actor domains and infrastructure
Public URL Redirect List (PURLs) – 1,200+ catalogued redirect services
PURLs Redirect Intercept Appliance – Pattern interrupt technology in action
[Request Access] to explore which feeds fit your security posture.
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